EXCLUSIVE: Sella McCartney has infuriated her neighbours in The Hamptons by building a 5ft high sea wall that blocks her community’s decades-old private access to its beach. The fashion designer and husband Alasdhair (correct) Willis paid $1.7million for their three-bedroom ocean front home and adjoining land three years ago. But erosion is claimed to have destroyed 40 feet of frontage in just one year so they joined with an adjacent neighbour to build the wall to save both properties. However, the imposing 230ft wide sandbag structure also runs across a beach entrance road between the two homes that is for everyone living in the private avenue. It slopes up on the avenue side but has had a 5ft sheer drop on to the beach since October last year because a storm washed away the sand that made it resemble a dune. This has made it impossible for most of the residents, many of them elderly, to get down on to the beach. Some neighbours, many having lived for decades in the quiet lane in Amagansett, Long Island, New York, have now branded the designer, 47, arrogant and high-handed. Despite The Hamptons being a millionaires’ playground with high property prices, most residents in the private avenue have lived there for many years and hold down regular jobs or are retired. Stella and her family are believed to have spent part of last summer at the modest 1176 sq ft home. She has four children with Alasdhair, the creative director at boot brand Hunter. The couple advertised the home as a summer rental in 2017 for up to $30,000 a month. Stella’s dad Sir Paul, 77, has had a home in uber-fashionable Amagansett since the 1990s and pal Gwyneth Paltrow, 46, also has a house there. Stella and the neighbour’s wall went up in July last year. But her permit with East Hampton council expired in April. She is now applying for a time extension– but is willing to remove the sandbags across the 30ft wide access and run them round the side of her house, according to the latest pape